In slicing wafers from hard materials, e.g., silicon ingots used in manufacturing photovoltaic cells, it is desirable to decrease costs by increasing material utilization i.e., wafers per linear inch of material, and also by decreasing expendable material costs, e.g., by increasing the blade life.
The wafer yield has been increased by using blades having abrasive particles embedded in only cutting portions, as is disclosed in Schmid U.S. Pat. No. 4,187,828, and by reducing the lateral wander of blades during cutting by minimizing vibrations and using guide rollers, as is taught in our patent application U.S. Ser. No. 201,247 filed Oct. 27, 1980 and entitled Multi-Wafer Slicing with a Fixed Abrasive, which application has been abandoned in favor of continuation application U.S. Ser. No. 421,120 filed Sept. 22, 1982.
The blade life has been increased by operating at high speeds, as is also taught in the above-mentioned patent application, and by reducing abrasive particle pullout by plating the entire surface of a wire blade having the abrasive particles already embedded in it, as is taught in U.S. Pat. No. 4,187,828. Plating the entire wire surface, however, results in increasing the width of the blade, thereby increasing the kerf width and decreasing the yield.